Article feeding mechanism



Feb. 27, 1951 D. v. WATERS ETAL v I 2,543,538

m'rrcm moms uEcumsu I Filed July 22, 1948 r 4 Sheets-Sheet 1 10 FIG.

mvavrons D. 1 WA TERS N. ZUCK By MM A T roAwer .Feb. 27, 1951 o. v. wATERs ETAL 2,543,538

. ARTICLE FEEDING ,HECHANISII Filed July 22, 1948 Y 4 Shets-Sheet 2 l N V E N TORS 0. 1 WA rs/as v. zuc/r ATTORNEY Patented Feb. 27, I951 UNITED STATES PATENT OFFICE ARTICLE FEEDING MECHANISM Daniel Vaughn Waters, Flemington, N. J., and Nicholas Zuclr, Brooklyn, N. Y., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application July 22, 1948, Serial No. 40,068

4 Claims.

This invention relates to article feeding mechanisms for sanding machines of the belt type, and has for its object, the provision of an article feeding mechanism, particularly efficient in moving articles such as synthetic crystals in a given direction relative to the sanding belt of a belt sanding machine under variable pressures and for measured distances to accurately reduce the dimensions of the work.

In the manufacture of synthetic crystals, commercially known as EDT crystals, produced from a solution of ethylene diamine tartrate for use in the communication arts, the mother stones are cut into wafers of given thicknesses and these wafers are to be reduced to final dimensions by moving them in a fixed path into engagement with a sanding belt while covering the working surface of the sanding belt with a liquid such as water which is a solvent for the synthetic crystals.

With the aforementioned object inview, the invention comprises an article feeding mechanism for a belt sanding machine having a sanding belt driven through a given plane, the article feeding mechanism including a table having taken along h means thereon to support an article, and parallel links to support the table for movement with the article relative to the sanding belt and to maintain the table at a given angle with respect to the said plane through which the belt travels.

More specifically, the article feeding fixture is the table in a loading position, while a variable force embodied in a spring acts to move the table with the article toward the sanding belt a given distance controlled by a variable stop measuring the thickness or dimensions to which the articles or crystal wafers are to be reduced by the sanding process. Also a weight-like unit secured to one of the links and positioned beneath the rocking element counterbalances the structure above the element in its movement toward and away from the sanding belt and also its movement about its axis of oscillation.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings. wherein Fig. 1 is a front elevational view of the work feeding mechanism mounted on a belt sanding machine, portions of the machine being broken away;

mounted on the belt sanding machine wherein the rollers for the sanding belt are positioned to cause the front portion of the belt which travels through the operating or working position to travel in a vertical plane relative to a fixed position backing member for the belt having its guiding face also lying in a vertical plane. The table of the article feeding mechanism supports a magnetic chuck to successively hold article supports at like positions on the table, the article supports being adapted to receive articles such as synthetic crystal wafers. The table is supported by pantograph links on a rocking element, the links permitting movement of the table with the article relative to the sanding belt, assuring maintenance of the table in a plane perpendicular with the sanding belt or that portion of the sanding belt traveling through the working position. The power means for the sanding belt drives a speed reducing unit, which in turn, drives a variable eccentric mechanism connected to the rocking element to rock it together with the table relative to the sanding belt between variable limits. A latch mechanism is provided to hold Fig. 2 is a side elevational view of the structure shown in Fig. 1;

Fig. 3 is an enlarged vertical sectional view of the work feeding mechanism, this view being line 3-3 of Fig. 1;

Fig. 4 is an enlarged fragmentary sectional view taken along the line 4-4 of Fig. 3;

Fig. 5 is an enlarged fragmentary sectional view taken along the line 5-5 of Fig. 1;

Fig. 6 is an enlarged fragmentary sectional view taken along the line 66 of Fig. 1; and

Fig. 7 is an isometric view of an article or synthetic crystal wafer.

Referring now to the drawings, attention is first directed to the sanding machine, portions of which are illustrated in Figs. 1 and 2. The sanding machine indicated generally at III includes a main housing ll supporting rollers l2, only one of which is shown in the drawings. The rollers support a sanding belt I4 and cause it to travel whereby the front portion thereof will travel in the direction of the arrow in a vertical plane relative to a backing member l5 whose forward surface l6 lies in a plane parallel with this portion of the sanding belt. The lower pulley I2 is driven through a belt l8 and pulley l9 connected to a power means such as an electric motor (not shown) The pulley IQ of this driving means is mounted on a shaft 20 of the lower roller l2, this shaft also having a pulley 2| mounted there on. The pulley 2| is connected to an input shaft 22 of a speed reducing unit 23 through a belt 24 and a pulley 25. The speed reducing unit 23 may be of the well-known gear reduction type having an output shaft 26, attention being dirooted to Figs. 2 and 5. A clutch member 21 is mounted on and keyed to the shaft 28 and supports companion clutch members 28 and 29. The clutch members 28 and 29 have annular friction members 30 and 3| fixed to their inner faces for engagement with the clutch member 21 under variable pressure incorporated in four springs 32 spaced equally about the clutch members. The positions of the springs 32 may be determined by viewing Fig. 1, although the springs are not shown in this figure, they being shown more in detail in Fig. 6. The springs 32 are positioned concentric with screws 34 extending through aligned apertures in the clutch member 29 and the friction member 3| where their threaded ends are receivable in threaded apertures 35 of the clutch member 28. Recesses 38 are formed in the clutch member 28 for the springs 32 and it will be apparent that rotation of the screws 34 in either direction will equally vary the forces in the springs 32 tending to draw the clutch members 28 and 29 toward each other to vary the gripping force between the clutch members 28-29 and the clutch element 21.

An eccentric unit 40 includes a plate 4| fixedly mounted on the clutch member 29 and provided with an aperture 42 to removably receive a pivot 43 of an arm 44. An arcuate elongate aperture 45 is formed in the plate 4| on the opposite side of the axis of the shaft 28 from the aperture 42 to receive a bolt 48 to lock the arm 44 in any selected position relative to the plate 4| within the adjustable distance controlled by the aperture 45. The arm 42 has a spindle 48 fixedly mounted therein for connection with a crank arm 49. The crank arm 49 as illustrated in Fig. '1 has its lower end 50 apertured to receive a threaded connecting rod 5| secured to the crank arm 49 in any selected position by the aid of lock nuts 52. The lower end of the crank arm 5| is pivotally connected at 53 to a rocking element 54 (Figs. 1, 2 and 3). The rocking element 54 is supported between spaced bearings 56 (Fig. 3) on aligned stub. shafts 51 carried by the hearings on bracket arms 59 and 80. The bracket arms 59 and B are mounted on the main housing II of the sanding machine in positions to locate the article feeding mechanism a desired distance from the working surface of the sanding belt.

A counterbalancing unit 82 is provided for the rocking element 54 and the structure mounted thereon and is positioned at the opposite side of the pivotal connection 53 (Fig. 1). The counterbalancing unit includes a threaded bracket 83 which extends inwardly beneath the axis of the rocking element to receive a selected number of weights 84. A table I0 is supported by pantograph links H which are mounted upon the rocking element 54. The links II are in integral pairs, the links of each pair being joined together by channel members I2. One of the links (Fig. 1) has a downwardly extending leg portion I3 to which the bracket 83 of the unit 52 is secured. A helical spring 14 provides a variable force normally urging the table toward the sanding belt. It will be noted by viewing Figs. 1 and 3 that the spring 74 is disposed concentric with a spindle I5, the axis of which is coincident with the axis of the lower pivotal support for the foremost pair of links II. One end I of the spring I4 extends upwardly and engages the front surface of the adjacent channel member I2, while the other end 11 of the spring I4 is positioned to be received in any one of a multiplicity of notches I8 of a control element 19. The control element I8 is annular in general contour and is mounted at a fixed position concentric with the spindle I5, the notches I8 being disposed dia onally as illustrated in Fig. 1 to assure locking of the end 11 of the spring against displacement. By adjusting the end 11, clockwise or counterclockwise, as the case may be, the force in the spring may be decreased or increased depending upon the force desired for moving the article or synthetic crystal against the sanding belt.

A latch 8| pivotally supported at 82 at its inner end to a bracket 83, mounted upon the rocking element 54, has one or more notches 84 in its under surface to receive a pin 85 carried by one of the foremost links II to hold the article feeding mechanism, particularly the table I0 thereof away from the belt I4 and in the loading position. A loop-like handle 88 mounted on the front edge of the table I0 is provided for manual movement of the table into its loading position at which time, the latch 8| will fall by gravity when the pin 85 registers with the notch 84.

In the present embodiment of the invention, the article holding means includes a metallic support 88 having suitable means on one face thereof to receive and support a given number of articles or synthetic crystals 89. In the present illustration, cross-bars 90 are formed upon or secured to the surface 9| of the support 88 to support the articles 89. No positive means is provided in the present instance to fix the articles 89 in place. A film of oil or suitable material covers the surface 9| and acts as a retaining means for the articles during the sanding operation. End members 92, having aligned diagonally extending elongate apertures 93 therein, are free to move thereby on supporting screws 94, carried at each side of the support 88. The end members function when in the holding position shown in Fig. 3 to limit movement of the articles 89 during sanding operation. Prior to mounting the support 88 upon the table, that is, when the articles 89 are being loaded on the support, or unloaded therefrom, the support will rest upon its under surface 98 and the end mem-- bers 92 will be moved to cause the-edges 91 thereof to be positioned short of or in a plane with a surface 9|.

A magnetic chuck I00 is mounted on the table I0 with its contacting surface I 0| positioned short of the leading edge I02 of the table 10, allowing a known distance on the table for mounting of the support 88. A switch I03 mounted in the magnetic chuck I00 may be rotated between given limits to open or close an electrical circuit (not shown) to deenergize or energize the magnetic chuck.

With the distance between the end IOI of the magnetic chuck and the leading end I02 of the table being known, and the thickness of the support 88 also being known, it is possible to control the movement of the articles 89 relative to the sanding belt I4 to cause reduction of the articles to given known dimensions. This is accomplished through the aid of a fixed stop I05 located on a bracket I06 mounted at I01 on the rocking element 54, functioning in combination with a movable adjustable stop I08. The movable stop I08, as well as the fixed stop I05 are formed of hardened steel parts to resist wear. Furthermore, the stop I05 is of a given contour for engagement with the movable stop I08 during arcuate movement thereof with the table I0. An internally threaded element I09 supports the stop I 08, this element being mounted upon an adjusting screw IIO which is supported for rotation in an aperture III in a downwardly extending portion 2 of the table 10. A knurled wheel II4 mounted on the outer end of the adjusting screw IIO facilitates the manual rotation of the screw to adjust the position of the stop I08 relative to the stop I05. It will be noted by viewing Fig. 4 that the threaded element I09 is supported by a substantially U-shaped member II5, the legs of which have V-shaped grooves II6 disposed in a common plane and positioned to ride on parallel tracks III which have V-shaped inner edges receivable in the grooves H6. The tracks II! are mounted at II8 beneath the table I0. A dial I having graduations I2I thereon movable relative to a pointer I22 on the table 10 functions to indicate the final dimension desired for the article being sanded and in this manner will indicate the distance between the surface 9| and the sanding belt controlled by the stops I08 and I05.

During the operation of the article feeding mechanism, it will be noted that the table I0 will be rocked between given limits depending upon the width of the support 88 and the movement desired to cause the articles to traverse substantially the full width of the sanding belt I4. In Fig. 1, the minimum limits are indicated at I25 while the maximum limits are indicated at I28. These limits are determined prior to starting operation of the machine and if variations are desired, they may be accomplished in one instance by loosening the screw 46 and moving the arm 44 about its pivot 43 within the aperture 45 to the desired position. Other variations may be made to center the limits relative to the sanding belt by varying the length of the connecting rod 48-5I through adjustment of the lock nuts 52. These adjustments having been completed, the next adjustment for consideration is the friction clutch shown in Fig. 5 to determine the driving force to be applied in oscillating or rocking the table with the article relative to the sanding belt. By adjusting the screws 34 to vary the forces embodied in the springs 32, the frictional forces created by the clutch members 28 and 29 through their friction elements 30 and ill on the clutch element 21, may be varied as desired. Another adjustment may be considered before starting the machine. This adjustment includes the spring 14 which determines the force applied through the table to the article in forcing the article against the sanding belt.

In the present illustration, the faces of a plurality of synthetic crystals are being'sanded or otherwise ground to correct the surfaces and reduce the thicknesses of the crystals. In other instances (not shown) a plurality of the crystals may be mounted in stacked formation to reduce the lengths or widths of'the crystals or articles. In these instances, it may be desirable to increase the force created in the spring 14 and the driving force of the friction clutch. Also the limits of movement of the table may require changing. The final adjustment essential is adjustment of the screw IIO, determined by the dial I20 and its graduations I2I moving relative to the pointer I22.

The apparatus is now in condition for operation for successively feeding similar articles to the sanding belt. By suitable means (not shown), a fluid such as water is fed to the sanding belt I4 during the sanding operation. The table I0 is initially in its loading position away from the sanding belt where it is held by the latch 8| engaging the pin 85. A support 88 supplied with articles 89 in their proper positions is located on the leading end of the table after which the magnetic chuck I00 is energized holding the support in this position. The latch 8| may be released by the operator moving the table to the right (Fig. 3) and then allowing the table to move slowly toward the sanding belt until the articles 89 engage the sanding belt. Operation of the machine continues until the stop I08 engages the stop I05 at which time the sanding operation has been completed.

It should be understood, however, that the pantograph links II maintain the table with the articles in a given relation with respect to the path of the sanding belt. The table will at all times lie in a plane perpendicular to the plane of the sanding belt, locating the surface 9| of the support 88 parallel with the plane of the sanding belt. During the continued travel of the sanding belt, the table with the articles are rocked between the selected limits under the driving force governed by the friction clutch. When the operation has been completed, the operator moves the table to the loading position where it is held by the latch 8|, after which the magnetic chuck I00 is deenergized, the present support 88 with its articles removed and another support loaded with articles to be sanded positioned upon the table adjacent the chuck I00 held in place by energization of the chuck and then moved into engagement with the sandingbelt for a sanding operation on the articles.

The counter-balancing unit 62 performs two important functions in counterbalancing the structure on the rocking element 54, one during operation thereof to rock the table with the article between the selected limits and another to allow the spring 74 to control the force applied to' the article in urging it toward the sanding belt. In the first instance, it will be observed that when the table I0 is in the neutral position shown in Fig. 1, the unit 62 is in its neutral position. However, movement of the table in either direction from its neutral position will move the unit 62 a comparable distance in the opposite direction to counterbalance this rocking structure, resulting in a smooth movement of the article relative to the sanding belt. In the second instance, it will be observed by viewing Fig. 2 that the weights 64 of the unit 62 are centrally positioned in a plane with the pivots of the foremost (at the right) pair of links 'II when the links H are in their neutral positions shown in this figure and also in Fig. 3. When the latch 8| is released and the spring 14 is free to apply its force to the article, through the links H, the table I0, the chuck I00 and the support 88, this force would be varied considerably if the structure above the rocking element 54 was not counterbalanced. For example, with the unit 62 removed, movement of the table toward the sanding beltfrom its neutral position would add a' weight-like force to the article, in addition to the force of the spring 14, comparable to the weight of the link II and the structure supported thereby. Movement of the table I0 to the right of its neutral position will apply this weight-like force against the force of the spring I4. The unit 62, therefore, counterbalances this weight-like force and allows the spring I4 to apply its selected variable force to the article.

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An article feeding mechanism, for a belt sanding machingliaving a sanding belt driven through a given plane, the article feeding mechanism comprising a table, means on the table to support an article, parallel links to support the table for movement with the article toward and away from the sanding belt and to maintain the table at a given angle with respect to the said plane through which the belt travels, a spring to apply a predetermined force to one of the links to move the links out of their neutral vertical positions with the table and article toward the sanding belt, and a unit connected -to one of the links and positioned to counterbalance the weight force of the links and the structure supported thereby including the table and the article whereby only the predetermined force of the spring will be applied to the article against the sanding belt.

. 2. An article feeding mechanism, for a belt sanding machine having a sanding belt driven through a given plane, the article feeding mechanism comprising a table, means on the table to support an article, parallel links to support the table for movement with the article to ward and away from the sanding belt and to maintain the table at a given angle with respect to the said plane through which the belt travels, a spring to apply a predetermined force to one of the links to move the links out of their neutral vertical positions with the table and article toward the sanding belt, a unit connected to one of the links and positioned to counterbalance the weight force of the links and the structure supported thereby including the table and the article whereby only the predetermined force of the spring will be applied to the article against the sanding belt, a rocking element interposed between the counterbalancing unit and the links to support the links with the table and article for oscillation in a path parallel with the said given plane of the sanding belt, and means to rock the element, the counterbalancing unit also functioning to counterbalance the links and the structure supported thereby during rocking of the element.

3. An article feeding mechanism, for a belt sanding machine having a sanding belt driven through a given plane, the article feeding mecha nism comprising a table, means on the table to support an article, parallel links pivotally secured at like ends to the table to support the table for movement with the article toward and away from the sanding belt and to maintain the table at a given angle with respect to the said plane through which the belt travels, an element mounted at a given position relative to the said plane of the belt pivotally supporting the other ends of the parallel links, a spring to apply a predetermined force to one of the links to move the links out of their neutral vertical positions with the table and article toward the sanding belt, and a weight rigidly mounted on one of the links and centrally positioned in a plane with its pivots to counterbalance the weight force of the links and the structure supported thereby including the table and the article whereby only the predetermined force of the spring will be applied to the article against the sanding belt.

4. .An article feeding mechanism, for a belt sanding machine having a sanding belt driven through a given plane, the article feeding mechaansim comprising a table, means on the table to support an article, parallel links pivotally secured at like ends to the table to support the table for movement with the article toward and away from the sanding belt and to maintain the table at a given angle with respect to the said plane through which the belt travels, a rocking element pivotally supporting the other ends of the parallel links and mounted for movement about an axis disposed at right angles to the pivots of the links, a spring to apply a predetermined force to one of the links to move the links out of their neutral vertical positions with the table and article toward the sanding belt, and a weight rigidly mounted on one of the links to normally lie in a plane with its pivots and also a vertical plane with the axis of the rocking element whereby, in one instance the weight will counterbalance the weight force of the links and the structure supported thereby including the article to render the spring eflfective to apply its force to the article against the sanding belt, and in another instance to counterbalance the links and structure supported thereby during rocking movement with the element.

DANIEL VAUGHN WATERS. NICHOLAS ZUCK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 826,694 Shirley July 24, 1906 1,548,562 Spencer Aug. 4, 1925 2,095,438 Hall Oct. 12, 1937 2,218,648 Kranich Oct. 22, 1940 2,398,628 Dykoski Apr. 16-, 1946 2,404,282 Fruth July 16, 1946 2,425,234 Erwin et al. Aug. 5, 1947 2,446,597 Kingsbury Aug. 10, 1948 

